I have an ST nva in my '57 .35 RH which, after turning the spraybar down to ~.125", allowed it to turn a 10-6 to a respectable rpm.
However, on my rotating test stand it was very slow to cycle from 4 to 2 and even slower to come back down to 4.
Needling was also erratic - 3/4 turn might do nothing, then a few degrees might add a couple hundred rpm.
The engine was fresh from a crock-potting and reassembly, so I chalked it up to a need for rebreak-in.
In an earlier thread, on hot plugs, Randy S. had cautioned that the spraybar might break from vibration in time, so I decided to try a remote, relieving it of the mass of the loooooong ST needle and collet nut.
I plugged one end and connected the other to a spare OS remote needle and it needled very linearly, and after about an hour's running 4-2-4'd quite well, with props from 9-6 to 11-6.
I reinstalled the ST needle, thinking now it might act like it has some manners.......but no.
When rotated 90 deg, it still takes a full second or more to go into 2 and at least 5 secs to come back to 4.
Same fuel, plug, props and tank on my test stand throughout.
Now, I have no prob running the remote, MOF I like not having my hand near a spinning prop, but since the ST nva is so often recommended for RH replacement, I'm wondering what the deal is with it.
Anyone have thoughts on why it's so crappy?
Terry